Systems, devices, and methods for curved waveguides integrated with curved eyeglass lenses

ABSTRACT

Systems, devices, and methods that implement waveguides in curved transparent combiners that are well-suited for use in wearable heads-up displays (WHUDs) are described. Waveguide structures with in-couplers and out-couplers are integrated with curved eyeglass lenses to provide transparent combiners that substantially match the shape, size, and geometry of conventional eyeglass lenses and can, in some implementations, embody prescription curvatures to serve as prescription eyeglass lenses. The waveguides and in-/out-couplers are planar or curved depending on the implementation. 
     WHUDs that employ such curved transparent combiners are also described.

TECHNICAL FIELD

The present systems, devices, and methods generally relate tointegrating waveguides with curved eyeglass lenses, and particularlyrelate to systems, devices, and methods that employ curved eyeglasslenses with waveguides integrated therewith in wearable heads-updisplays.

BACKGROUND Description of the Related Art Wearable Heads-Up Displays

A head-mounted display is an electronic device that is worn on a user'shead and, when so worn, secures at least one electronic display within aviewable field of at least one of the user's eyes. A wearable heads-updisplay is a head-mounted display that enables the user to see displayedcontent but also does not prevent the user from being able to see theirexternal environment. The “display” component of a wearable heads-updisplay is either transparent or at a periphery of the user's field ofview so that it does not completely block the user from being able tosee their external environment. The “combiner” component of a wearableheads-up display is the physical structure where display light andenvironmental light merge as one within the user's field of view. Thecombiner of a wearable heads-up display is typically transparent toenvironmental light but includes some optical routing mechanism todirect display light into the user's field of view.

Examples of wearable heads-up displays include: the Google Glass®, theOptinvent Ora®, the Epson Moverio®, and the Microsoft Hololens® just toname a few.

Optical Waveguides in Wearable Heads-Up Displays

A majority of currently available wearable heads-up displays employoptical waveguide systems in the transparent combiner. An opticalwaveguide operates under the principle of total internal reflection(TIR). TIR occurs when light remains in a first medium upon incidence ata boundary with a second medium because the refractive index of thefirst medium is greater than the refractive index of the second mediumand the angle of incidence of the light at the boundary is above aspecific critical angle that is a function of those refractive indices.Optical waveguides employed in wearable heads-up displays like thosementioned above typically consist of rectangular prisms of material witha higher refractive index then the surrounding medium, usually air(Google Glass®, Optinvent Ora®, Epson Moverio®) or a planar lens(Microsoft Hololens®). Light input into the prism will propagate alongthe length of the prism as long as the light continues to be incident atboundaries between the prism and the surrounding medium at an angleabove the critical angle. Optical waveguides employ in-coupling andout-coupling elements to ensure that light follows a specific path alongthe waveguide and then exits the waveguide at a specific location inorder to create an image that is visible to the user.

The optical performance of a wearable heads-up display is an importantfactor in its design. When it comes to face-worn devices, however, usersalso care a lot about aesthetics. This is clearly highlighted by theimmensity of the eyeglasses (including sunglasses) frame industry.Independent of their performance limitations, many of the aforementionedexamples of wearable heads-up displays have struggled to find tractionin consumer markets because, at least in part, they lack fashion appeal.Most wearable heads-up displays presented to date employ planarwaveguides in planar transparent combiners and, as a result, appear verybulky and unnatural on a user's face compared to the more sleek andstreamlined look of typical curved eyeglass and sunglass lenses. Thereis a need in the art to integrate curved eyeglass lenses with waveguidesin wearable heads-up displays in order to achieve the form factor andfashion appeal expected of the eyeglass frame industry.

BRIEF SUMMARY

A wearable heads-up display may be summarized as including: a supportstructure that in use is worn on a head of a user; a display lightsource to provide display light; and a transparent combiner carried bythe support structure and positioned in a field of view of an eye of theuser when the support structure is worn on the head of the user, thetransparent combiner including: a curved waveguide; an in-couplerphysically coupled to a first area of the curved waveguide, thein-coupler to receive display light from the display light source andin-couple display light into the curved waveguide; and an out-couplerphysically coupled to a second area of the curved waveguide, theout-coupler to receive display light from the curved waveguide andout-couple display light into the field of view of the eye of the user.The in-coupler and the out-coupler may each be selected from a groupconsisting of: a hologram, a holographic optical element, a volumediffraction grating, a surface relief diffraction grating, atransmission grating, and a reflection grating.

The first area of the curved waveguide to which the in-coupler isphysically coupled may be an area on an outer surface of the curvedwaveguide. The second area of the curved waveguide to which theout-coupler is physically coupled may be an area on an inner surface ofthe curved waveguide.

The transparent combiner may further include a curved eyeglass lens,wherein the curved waveguide is at least partially embedded in an innervolume of the curved eyeglass lens. The curved waveguide may becompletely contained in the inner volume of the curved eyeglass lens.The curved eyeglass lens may be a prescription eyeglass lens. Theprescription eyeglass lens may have a prescription curvature. Acurvature of the curved waveguide may match the prescription curvatureof the prescription eyeglass lens. The curved eyeglass lens may includea convex world-side surface and a concave eye-side surface. Theout-coupler may be positioned and oriented to apply a compensatoryoptical function to display light when the out-coupler out-couplesdisplay light from the curved waveguide. The compensatory opticalfunction may be matched to an optical function of the convex world-sidesurface of the curved eyeglass lens. A length of the curved waveguidemay extend across a full width of the curved eyeglass lens. The secondarea of the curved waveguide to which the out-coupler is physicallycoupled may be positioned at or proximate a center of the curvedeyeglass lens.

The first area of the curved waveguide may be a first planar area of thecurved waveguide and the second area of the curved waveguide may be asecond planar area of the curved waveguide. The in-coupler may be aplanar in-coupler physically coupled to the first planar area of thecurved waveguide and the out-coupler may be a planar out-couplerphysically coupled to the second planar area of the curved waveguide.

The first area of the curved waveguide may be a first curved area of thecurved waveguide and the second area of the curved waveguide may be asecond curved area of the curved waveguide. The in-coupler may be acurved in-coupler physically coupled to the first curved area of thecurved waveguide and the out-coupler may be a curved out-couplerphysically coupled to the second curved area of the curved waveguide.

The display light source may be selected from a group consisting of: alaser projector and a microdisplay.

The support structure may have a shape and geometry of a pair ofeyeglasses.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

In the drawings, identical reference numbers identify similar elementsor acts. The sizes and relative positions of elements in the drawingsare not necessarily drawn to scale. For example, the shapes of variouselements and angles are not necessarily drawn to scale, and some ofthese elements are arbitrarily enlarged and positioned to improvedrawing legibility. Further, the particular shapes of the elements asdrawn are not necessarily intended to convey any information regardingthe actual shape of the particular elements, and have been solelyselected for ease of recognition in the drawings.

FIG. 1 is a sectional view showing a transparent combiner for use in awearable heads-up display in accordance with an embodiment of thepresent systems, devices, and methods.

FIG. 2 is a sectional view showing a transparent combiner for use in awearable heads-up display in accordance with another embodiment of thepresent systems, devices, and methods.

FIG. 3 is a sectional view showing a transparent combiner for use in awearable heads-up display in accordance with another embodiment of thepresent systems, devices, and methods.

FIG. 4 is an illustrative diagram showing an example of a wearableheads-up display employing a curved transparent combiner in accordancewith an embodiment of the present systems, devices, and methods.

FIG. 5 is a sectional view showing a transparent combiner for use in awearable heads-up display in accordance with another embodiment of thepresent systems, devices, and methods.

FIG. 6 is a sectional view showing a transparent combiner for use in awearable heads-up display in accordance with another embodiment of thepresent systems, devices, and methods.

DETAILED DESCRIPTION

In the following description, certain specific details are set forth inorder to provide a thorough understanding of various disclosedembodiments. However, one skilled in the relevant art will recognizethat embodiments may be practiced without one or more of these specificdetails, or with other methods, components, materials, etc. In otherinstances, well-known structures associated with portable electronicdevices and head-worn devices, have not been shown or described indetail to avoid unnecessarily obscuring descriptions of the embodiments.

Unless the context requires otherwise, throughout the specification andclaims which follow, the word “comprise” and variations thereof, suchas, “comprises” and “comprising” are to be construed in an open,inclusive sense, that is as “including, but not limited to.”

Reference throughout this specification to “one embodiment” or “anembodiment” means that a particular feature, structures, orcharacteristics may be combined in any suitable manner in one or moreembodiments.

As used in this specification and the appended claims, the singularforms “a,” “an,” and “the” include plural referents unless the contentclearly dictates otherwise. It should also be noted that the term “or”is generally employed in its broadest sense, that is as meaning “and/or”unless the content clearly dictates otherwise.

The headings and Abstract of the Disclosure provided herein are forconvenience only and do not interpret the scope or meaning of theembodiments.

The various embodiments described herein provide systems, devices, andmethods for curved eyeglass lenses with planar waveguides integratedtherewith. Curved eyeglass lenses with planar waveguides embeddedtherewith are particularly well-suited for use as or in the transparentcombiner of wearable heads-up displays (“WHUDs”) in order to enable theWHUDs to adopt more aesthetically-pleasing styles and, in someimplementations, to enable the WHUDs to include prescription eyeglasslenses. Examples of WHUD systems, devices, and methods that areparticularly well-suited for use in conjunction with the presentsystems, devices, and methods for curved lenses with planar waveguidesare described in, for example, U.S. Non-Provisional patent applicationSer. No. 15/167,458 (now US Patent Application Publication No. US2016-0349514 A1), U.S. Non-Provisional patent application Ser. No.15/167,472 (now US Patent Application Publication No. US 2016-0349515A1), U.S. Non-Provisional patent application Ser. No. 15/167,484 (now USPatent Application Publication No. US 2016-0349516 A1), US PatentApplication Publication No. US 2016-0377865 A1, US Patent ApplicationPublication No. US 2016-0377866 A1, and US Patent ApplicationPublication No. US 2016-0238845 A1.

FIG. 1 is a sectional view showing a transparent combiner 100 for use ina WHUD in accordance with the present systems, devices, and methods.Transparent combiner 100 includes a curved eyeglass lens 101 which mayor may not be a prescription eyeglass lens depending on the specificimplementation. At least partially embedded in an inner volume 102 ofcurved eyeglass lens 101 is a planar waveguide structure 110. Planarwaveguide 110 may be a conventional rectangular prism structure formedof a material with an index of refraction that is sufficiently differentfrom that of curved eyeglass lens 101 to enable TIR within planarwaveguide 110 through the inner volume 102 of curved eyeglass lens 101.In order to enable display light to couple into planar waveguide 110,transparent combiner 100 includes a planar in-coupler 121 physicallycoupled to a first area 111 of planar waveguide 110. Similarly, in orderto enable display light to couple out of planar waveguide 110,transparent combiner 110 includes a planar out-coupler 122 physicallycoupled to a second area 112 of planar waveguide 110. The display lightthat in-couples through in-coupler 121 and out-couples throughout-coupler 122 may originate from a display light source, such as aprojector, a scanning laser projector, a microdisplay, or similar. Inuse, planar in-coupler 121 receives display light from a display lightsource and in-couples display light into planar waveguide 110, andplanar out-coupler 122 receives display light from planar waveguide 110and out-couples display light into the field of view of the eye of theuser. A person of skill in the art will appreciate that additionaloptics may be employed in between the display light source andin-coupler 121 and/or in between out-coupler 122 and the eye of the userin order to shape the display light for viewing by the eye of the user.

A representative example of a path of display light through planarwaveguide 110 is illustrated by the arrows in FIG. 1.

Throughout this specification and the appended claims, the term“waveguide” is used in a general sense to refer to a transparent opticalstructure through the inner volume of which display light is propagatedby TIR. Unless the specific context requires otherwise, the term“waveguide” is not meant to impart or require any features orlimitations with respect to the wave nature of light (e.g., “single modewaveguide”) and should be understood to be interchangeable with relatedterms for functionally similar structures known in the field of optics,such as “lightguide” or “lightpipe.”

Throughout this specification and the appended claims, the terms“in-coupler” and “out-coupler” are generally used to refer to any typeof optical grating structure, including without limitation: diffractiongratings, holograms, holographic optical elements (e.g., opticalelements employing one or more holograms), volume diffraction gratings,volume holograms, surface relief diffraction gratings, and/or surfacerelief holograms. Depending on the specific implementation (e.g.,depending on the specific position of the in-coupler or out-coupler),the in-couplers/out-couplers herein may be of the transmission type(meaning they allow the display light to transmit therethrough and applytheir designed optical function(s) to the light during suchtransmission) in which case they are referred to as “transmissionin-/out-couplers,” or they may be of the reflection type (meaning theyreflect the display light and apply their designed optical function(s)to the light during such reflection) in which case they are referred toas “reflection in-/out-couplers.”In the illustrated implementation ofFIG. 1, in-coupler 121 and out-coupler 122 are both transmissiongratings positioned on respective areas 111, 112 of an outer surface 130of planar waveguide 110; however, in alternative implementations eitheror both of in-coupler 121 and/or out-coupler 122 may be a transmissiongrating positioned on an inner surface 132 of planar waveguide 110and/or either or both of in-coupler 121 and/or out-coupler 122 may be areflection grating (in the latter case, a reflection grating would bepositioned on an inner/outer surface of planar waveguide 110 that isopposite the surface upon which gratings 121, 122 are illustrated inFIG. 1, across a thickness of planar waveguide 110).

In the illustrated implementation of FIG. 1, planar waveguide 110 iscompletely embedded in the inner volume 102 of curved eyeglass lens 101,meaning that all surface of planar waveguide 110 are fully enclosed bythe material of curved eyeglass lens 101. In alternativeimplementations, a planar waveguide may be only partially embedded orcontained within the inner volume of a curved eyeglass lens.

FIG. 2 is a sectional view showing another transparent combiner 200 foruse in a WHUD in accordance with the present systems, devices, andmethods. Transparent combiner 200 is similar to transparent combiner 100from FIG. 1 in that transparent combiner 200 includes a curved eyeglasslens 201 and a planar waveguide 210 with an in-coupler 221 coupled to afirst area 211 thereof and an out-coupler 222 coupled to a second area212 thereof; however, in transparent combiner 200 planar waveguide 210is not completely embedded in the inner volume 202 of curved eyeglasslens 201. Instead, planar waveguide 210 has a first end 231 physicallyembedded in a first region 241 (e.g., physically coupled to a firstpoint in first region 241) of curved eyeglass lens 210 and a second end232 (opposite first end 231 across a length of planar waveguide 210)physically embedded in a second region 242 (e.g., physically coupled toa second point in second region 242) of curved eyeglass lens 201. Inthis way, planar waveguide 210 forms a kind of “bridge” across regions241 and 242 on a curved surface of curved eyeglass lens 201. In theillustrated implementation of FIG. 2, in-coupler 221 and out-coupler 222are both reflection gratings positioned on respective areas 211, 212 ofan inner surface 230 of planar waveguide 210.

A representative example of a path of display light through planarwaveguide 210 is illustrated by the arrows in FIG. 2.

In FIG. 1, planar waveguide 110 is completely embedded within an innervolume of curved eyeglass lens 101, but planar waveguide 110 onlyextends across a portion of a total width of curved eyeglass lens 101.This is perfectly acceptable for some applications; however, an end 141of planar waveguide 110 within the inner volume 102 of curved eyeglasslens 101 can produce a seam that may be visible to the user and/or otherpeople in close proximity to the user. Such a seam can be undesirable inapplications where aesthetics of the WHUD are particularly important. Inorder to prevent the formation/presence of such a visible seam, thelength of the planar waveguide may be extended across the full width ofthe curved eyeglass lens. Such a configuration requires that thecurvature and thickness of the curved eyeglass lens provide an innervolume capable of accommodating a planar structure across its fullwidth.

Throughout this specification and the appended claims, the term “fullwidth” is used in a loose sense to generally refer to “at least 90% ofthe total width.”

FIG. 3 is a sectional view showing another transparent combiner 300 foruse in a WHUD in accordance with the present systems, devices, andmethods. Transparent combiner 300 is similar to transparent combiner 100from FIG. 1 in that transparent combiner 300 includes a curved eyeglasslens 301 with a planar waveguide 310 completely embedded in the innervolume 302 thereof, and with planar waveguide 310 including anin-coupler 321 coupled to a first area 311 thereof and an out-coupler322 coupled to a second area 312 thereof; however, in transparentcombiner 300 a length L of planar waveguide 310 extends across a fullwidth W of curved eyeglass lens 301. As previously described, thisconfiguration helps prevent seams corresponding to the edges or ends ofplanar waveguide 310 from being visible in the inner volume 302 ofcurved eyeglass lens 301. A further benefit of this configuration isthat it provides greater flexibility for where planar out-coupler 322 ispositioned within the field of view of the user. In the illustratedexample of FIG. 3, the second area 312 of planar waveguide 310 to whichplanar out-coupler 322 is physically coupled is positioned at orproximate a center of curved eyeglass lens 301 such that display light(represented by arrows in FIG. 3) generally appears in the user's fieldof view when the user is gazing straight ahead.

Depending on the particular needs of the user, curved eyeglass lens 301may be a prescription eyeglass lens (i.e., if the user typicallyrequires corrective lenses) or a non-prescription/“plano” eyeglass lens(i.e., if the user typically does not require corrective lenses). Ineither case, eyeglass lens 301 is advantageously curved for at leastaesthetic purposes. Furthermore, at least two surfaces of eyeglass lens301 are advantageously curved.

Eyeglass lens 301 includes a world-side surface 351 and an eye-sidesurface 352. When transparent combiner 300 is mounted in a WHUD system(e.g., in an eyeglasses frame) and worn on the head of the user,world-side surface 351 faces outward from the user towards the user'senvironment and eye-side surface 352 faces inward towards the eye of theuser. The curvature of eyeglass lens 301 is such that world-side surface351 is a convex surface and eye-side surface 352 is a concave surface.In implementations for which eyeglass lens 301 is a prescriptioneyeglass lens, either or both of convex world-side surface 351 and/orconcave eye-side surface 352 may embody a curvature that imparts anoptical function on environmental light that is transmitted througheyeglass lens 301. When convex world-side surface 351 embodies acurvature that imparts an optical function (e.g., optical power) onenvironmental light passing therethrough, out-coupler 322 mayadvantageously be designed, configured, positioned, and/or oriented toapply a compensatory optical function to display light that isout-coupled by out-coupler 322. Generally, the compensatory opticalfunction applied by out-coupler 322 may be matched (i.e., at leastapproximately equal to within 20% or less) to the optical function ofconvex world-side surface 351 of curved eyeglass lens 301. In otherwords, out-coupler 322 is generally operable to out-couple display lightfrom planar waveguide 310, and in doing so, out-coupler 322 may befurther operable to apply a compensatory optical function to the displaylight in order to cause the display light to appear as though it haspassed through convex world-side surface 351 even though the displaylight has not passed through convex world-side surface 351 but ratherhas propagated through planar waveguide 310 at least partially embedderdin the inner volume 302 of eyeglass lens 301.

The various embodiments described herein generally provide systems,devices, and methods for at least partially embedding at least a portionof a planar waveguide in at least a portion of an inner volume of acurved eyeglass lens. Such embedding may be achieved using a variety ofdifferent processes and techniques depending on the requirements of thespecific implementation. For example, at least a portion of a planarwaveguide may be at least partially embedded in at least a portion of acurved eyeglass lens by a molding/casting process in which the at leasta portion of the planar waveguide to be embedded in the curved eyeglasslens is positioned in a mold and the mold is then filled with a liquidmaterial (e.g., resin) via an injection process. The liquid material maythen be cured to form the rigid structure of the eyeglass lens and theremoved from the mold. Alternatively, at least a portion of a planarwaveguide may be at least partially embedded in at least a portion of acurved eyeglass lens by a lamination process, or by sandwiching togethertwo halves (more generally, “portions”) of the curved eyeglass lensaround the planar waveguide using an optically transparent adhesive.

Implementations of the present systems, devices, and methods thatinvolve lens casting/molding and/or that embed physical structures(e.g., planar waveguide 110) in the inner volume of a lens may do sousing the systems, methods, and devices described in US PatentApplication Publication No. 2017-0068095, U.S. Provisional PatentApplication Ser. No. 62/534,099, and/or U.S. Provisional PatentApplication Ser. No. 62/565,677.

As previously described, U.S. Non-Provisional patent application Ser.No. 15/167,458 (now US Patent Application Publication No. US2016-0349514 A1), U.S. Non-Provisional patent application Ser. No.15/167,472 (now US Patent Application Publication No. US 2016-0349515A1), U.S. Non-Provisional patent application Ser. No. 15/167,484 (now USPatent Application Publication No. US 2016-0349516 A1), US PatentApplication Publication No. US 2016-0377865 A1, US Patent ApplicationPublication No. US 2016-0377866 A1, and US Patent ApplicationPublication No. US 2016-0238845 A1 all describe WHUD architectures thatare well-suited to be adapted to use the transparent combiners 100, 200,and/or 300 described in the present systems, devices, and methods. Ageneral example of such a WHUD is depicted in FIG. 4.

FIG. 4 is an illustrative diagram showing an example of a WHUD 400employing a curved transparent combiner 401 in accordance with anembodiment of the present systems, devices, and methods. WHUD 400generally includes a support structure 410 that has the shape/geometryof a pair of eyeglasses and in use is worn on the head of the user.Support structure 410 carries a display light source 420 (e.g., a laserprojector or a microdisplay, which may or may not be at least partiallycontained within an inner volume of support structure 410) and alsocarries curved transparent combiner 401 which is positioned in a fieldof view of an eye of the user when support structure 410 is worn on thehead of the user. Curved transparent combiner 401 may include any oftransparent combiner 100 from FIG. 1, transparent combiner 200 from FIG.2, transparent combiner 300 from FIG. 3, or any combination or variationthereof. Generally, transparent combiner 401 is shown as a curvedeyeglass lens including a waveguide portion 440 (shown in dashed linesto indicate that it may not actually be visible to the user) and anout-coupler 430. A representative optical path of light from displaylight source 420 is illustrated with arrows in FIG. 4. The display lightleaves source 420 and enters waveguide 440 of transparent combiner 401(e.g., through an in-coupler, not visible in the view of FIG. 4), whereit is totally internally reflected until it reaches out-coupler 430,from whence it emerges and is directed towards the eye of the user (witha compensatory optical function applied thereto in some cases, aspreviously described).

Transparent combiners 100, 200, and 300 all generally employ a planarwaveguide (110, 210, 310) at least partially embedded in an inner volume(102, 202, 302) of a curved eyeglass lens (101, 201, 301). In someapplications, it may be advantageous to employ a curved waveguide ratherthan a planar waveguide. For example, a curved waveguide may offer theadvantage of more easily and seamlessly integrating with a curvedeyeglass lens; however, a curved waveguide may also introduce additionalcomplexity in the design and operation of the waveguide itself, suchcomplexity arising from the fact that display light internallyreflecting within the curved waveguide necessarily reflects from curvedsurfaces as opposed to planar surfaces. Such can add distortions to thedisplay light and require careful characterization of the display lightoptical paths in order to ensure that the critical angle threshold forTIR continues to be satisfied over the range of angles of incidenceimposed by the curved reflecting surfaces.

FIG. 5 is a sectional view showing another transparent combiner 500 foruse in a WHUD in accordance with the present systems, devices, andmethods. Transparent combiner 500 includes a curved waveguide 501 havinga first area 511 at which is physically coupled an in-coupler 521 and asecond area 512 at which is physically coupled an out-coupler 522. Otherthan the fact that waveguide 501 is curved as opposed to planar (such aswaveguides 110, 210, and 310), many of the features and descriptions oftransparent combiners 100, 200, and 300 may apply to transparentcombiner 500 (e.g., with respect to materials, the nature and operationof in-coupler 521 and out-coupler 522, etc.).

In some implementations, the curvature of curved waveguide 501 maycorrespond to a prescription curvature of a prescription eyeglass lens,in which case curved waveguide 5301 may also function as a curvedeyeglass lens (e.g., similar to curved eyeglass lens 101 fromtransparent combiner 100 and/or curved eyeglass lens 201 fromtransparent combiner 200). That is, curved waveguide 501 may itself be(i.e., also perform as) a curved eyeglass lens and may embody, forexample, a prescription curvature. In other implementations (and in theillustrated implementation of FIG. 5), curved waveguide 501 may beintegrated with a curved eyeglass lens 550. For example, curvedwaveguide 501 may be completely embedded and contained in an innervolume 502 of curved eyeglass lens 550. In this case, curved eyeglasslens 550 may be a prescription eyeglass lens having a prescriptioncurvature and the curvature of curved waveguide 501 may match theprescription curvature of prescription eyeglass lens 550.

Eyeglass lens 550 includes a world-side surface 551 and an eye-sidesurface 552. When transparent combiner 300 is mounted in a WHUD system(e.g., in an eyeglasses frame) and worn on the head of the user,world-side surface 551 faces outward from the user towards the user'senvironment and eye-side surface 552 faces inward towards the eye of theuser. The curvature of eyeglass lens 550 is such that world-side surface551 is a convex surface and eye-side surface 552 is a concave surface.In implementations for which eyeglass lens 550 is a prescriptioneyeglass lens, either or both of convex world-side surface 551 and/orconcave eye-side surface 552 may embody a curvature that imparts anoptical function on environmental light that is transmitted througheyeglass lens 550. When convex world-side surface 551 embodies acurvature that imparts an optical function (e.g., optical power) onenvironmental light passing therethrough, out-coupler 522 mayadvantageously be designed, configured, positioned, and/or oriented toapply a compensatory optical function to display light that isout-coupled by out-coupler 522. Generally, the compensatory opticalfunction applied by out-coupler 522 may be matched (i.e., at leastapproximately equal to within 20% or less) to the optical function ofconvex world-side surface 551 of curved eyeglass lens 550. In otherwords, out-coupler 522 is generally operable to out-couple display lightfrom curved waveguide 501, and in doing so, out-coupler 522 may befurther operable to apply a compensatory optical function to the displaylight in order to cause the display light to appear as though it haspassed through convex world-side surface 551 of eyeglass lens 550 eventhough the display light has not passed through convex world-sidesurface 551 of eyeglass lens 550 but rather has propagated throughcurved waveguide 501 at least partially embedded in the inner volume 502of eyeglass lens 550.

Similar to planar waveguide 310 from FIG. 3, the length of curvedwaveguide 501 extends across (i.e., is at least approximately equal towithin about 10%) the full width of curved eyeglass lens 550 in order toreduce the likelihood of visible “seams” at the edges of waveguide 501,and further to facilitate placement of second area 512 of curvedwaveguide 501 to which out-coupler 522 is physically coupled in aposition that is at or proximate a center of curved eyeglass lens 550.

As described previously, curved waveguide 501 has a first area 511 atwhich is physically coupled in-coupler 521 and a second area 512 atwhich is physically coupled out-coupler 522. In the illustratedimplementation of FIG. 5, first area 511 and second area 512 arerespective planar areas of curved waveguide 501. That is, first area 511of curved waveguide 501 is a first planar area 511 of curved waveguide501 and second area 512 of curved waveguide 501 is a second planar area512 of curved waveguide 501. First area 511 and second area 512 areplanar areas in FIG. 5 to facilitate receiving and carrying planarin-coupler 521 and planar out-coupler 522, respectively. In someimplementations (such as that illustrated in FIG. 5), it is advantageousfor in-coupler 521 to be a planar in-coupler 521 and for out-coupler 522to be a planar out-coupler 522 because a planar in-/out-coupler isgenerally simpler to design and manufacture than a curvedin-/out-coupler. Thus, in order to accommodate planer in-coupler 521,first area 511 of curved waveguide 501 is a planar first area 511 and,in order to accommodate planar out-coupler 522, second area 512 ofcurved waveguide 501 is a planar second area 512. Either or both ofplanar areas 511, 512 may be implemented as a respective planar surfaceon one side of curved waveguide 501 (such that the opposing surfaceacross a thickness of curved waveguide 501 is a continuous curvedsurface) or as a respective planar segment of curved waveguide 501 (suchthat the opposing surface across a thickness of curved waveguide 501 isa parallel planar surface).

Planar out-coupler 522 may, in some implementations, be designed,operable, positioned, and/or oriented to apply a compensatory opticalfunction to display light that it out-couples from curved waveguide 501.The compensatory optical function may relate to the optical functionimparted by the curvature of the convex world-side surface 551 ofeyeglass lens 550 as previously described, and/or the compensatoryoptical function may counteract any distortions that may result from theposition and orientation of planar out-coupler 522 in relation toconcave eye-side surface 552 of curved eyeglass lens 550.

First planar area 511 and second planar area 512 may be formed byetching, grinding, or otherwise shaping surfaces of curved waveguide501. Alternatively, curved waveguide 501 may be cast in a moldingprocess and the molds themselves may include first and second planarareas 511, 512 on the otherwise curved surface of curved waveguide 501.

Curved waveguide 501 may be integrated with curved eyeglass lens 550using any of the processes and techniques (e.g., molding, casting,laminating, sandwiching, etc.) described previously in relation to theintegration of a planar waveguide (110, 210, 310) with a curved lens(101, 201, 301), with the distinction that nay molds, processes, etc.must accommodate the curvature of curved waveguide 501.

A representative example of a path of display light through curvedwaveguide 501 is illustrated by the arrows in FIG. 5.

As an alternative to the implementation of FIG. 5 where first area 511and second area 512 are respective planar areas (and, correspondingly,in-coupler 521 and out-coupler 522 are respective planar couplers),curved areas and curved couplers may be used.

FIG. 6 is a sectional view showing another transparent combiner 600 foruse in a WHUD in accordance with the present systems, devices, andmethods. Transparent combiner 600 is substantially similar totransparent combiner 500 from FIG. 5, and many of the same features anddescription apply, except that in transparent combiner 600 in-coupler621 is a curved in-coupler 621 and out-coupler 622 is a curvedout-coupler 622. In brief, transparent combiner 600 includes a curvedwaveguide 601 having a first curved area 611 at which curved in-coupler621 is physically coupled and a second curved area 612 at which curvedout-coupler 622 is physically coupled. Curved waveguide 601 may itselfserve as a curved eyeglass lens or, as in the illustrated embodiment ofFIG. 6, curved waveguide 601 may be integrated with (e.g., embedded inthe inner volume of) a curved eyeglass lens 650.

Curved out-coupler 622 may be designed, operable, positioned, and/ororiented to compensate for (e.g., counteract) a convergence imparted ondisplay light out-coupled thereby due to the concave curvature of curvedout-coupler 622 and to cause display light out-coupled thereby topropagate along parallel optical paths as represented by the arrows inFIG. 6.

Implementations of the present systems, devices, and methods that employcurved in-/out-couplers may, as appropriate, employ the systems,devices, and methods described in US Patent Application Publication No.US 2017-0212290 A1.

Returning briefly to FIG. 4, in an alternative implementation to thatdescribed previously transparent combiner 401 of WHUD 400 may employ acurved waveguide 440 and either a planar or a curved out-coupler 430depending on the specific requirements of the application. That is,either transparent combiner 500 of FIG. 5 or transparent combiner 600 ofFIG. 6 may be used as transparent combiner 401 in WHUD 400 of FIG. 4.

In some implementations, a waveguide may terminate at the out-couplerbecause there is no desire to propagate light within the waveguidebeyond that point. However, as previously described, this can result ina visible seam within or upon the eyeglass lens where the waveguideends. In order to avoid this seam, in some implementations, a waveguidemay be extended beyond the out-coupler to the far edge of an eyeglasslens even though there is no intention to propagate light within thewaveguide beyond the out-coupler (as illustrated in FIG. 3).

In some implementations, a refractive index barrier (i.e., a materialhaving an intermediate refractive index) may be employed in between anin-coupler/out-coupler and any lens/waveguide material in order toenable light to couple between the in-coupler/out-coupler and thelens/waveguide material.

In some implementations, an air gap may be included to separate thesurfaces of the planar/curved waveguide from the surfaces of the curvedeyeglass lens and achieve a maximum difference in the refractive indexacross the interface of the planar/curved waveguide. In other words, airgaps may be used to deliberately separate the TIR surfaces of theplanar/curved waveguide (i.e., the surfaces of the planar/curvedwaveguide from which display light is totally internally reflected inuse) from the curved eyeglass lens material (i.e., no physical contacttherebetween) to maximize the change in refractive index at the surfaceof the planar/curved waveguide and facilitate TIR. In otherimplementations, a low-refractive index coating may be applied to theTIR surface(s) of the planar/curved waveguide instead of an air gap.

Some of the waveguides or in-couplers/out-couplers described herein(particularly those that employ curvature) may introduce opticaldistortions in displayed images. In accordance with the present systems,devices, and methods, such optical distortions may be corrected (i.e.,compensated for) in the software that drives the display engine. Forexample, the geometrical output of the transparent combiner may bemeasured without any compensation measure in place and a reversetransform of such output may be applied in the generation of light bythe display light source.

The relative positions of waveguides within lenses/combiners shownherein are used for illustrative purposes only. In some implementations,it may be advantageous for a waveguide to be positioned centrally withina combiner, whereas in other implementations it may be advantageous fora waveguide to be positioned off-center. In particular, it may beadvantageous for a waveguide to couple to the corner of the supportstructure/glasses frame where the temple of the glasses frame meets therims, because this is an advantageous location to route display lightfrom a scanning laser projector or microdisplay with minimal impact onform factor.

The various embodiments described herein generally reference a singleeye of a user (i.e., monocular applications), but a person of skill inthe art will readily appreciate that the present systems, devices, andmethods may be duplicated in a WHUD in order to provide binocularapplications.

The WHUDs described herein may include one or more sensor(s) (e.g.,microphone, camera, thermometer, compass, and/or others) for collectingdata from the user's environment. For example, one or more camera(s) maybe used to provide feedback to the processor of the wearable heads-updisplay and influence where on the transparent display(s) any givenimage should be displayed.

The WHUDs described herein may include one or more on-board powersources (e.g., one or more battery(ies)), a wireless transceiver forsending/receiving wireless communications, and/or a tethered connectorport for coupling to a computer and/or charging the one or more on-boardpower source(s).

The waveguides described herein may employ any of the systems, devices,and/or methods described in U.S. Provisional Patent Application Ser. No.62/525,601, U.S. Provisional Patent Application Ser. No. 62/557,551,U.S. Provisional Patent Application Ser. No. 62/557,554, and/or U.S.Provisional Patent Application Ser. No. 62/573,978.

Throughout this specification and the appended claims the term“communicative” as in “communicative pathway,” “communicative coupling,”and in variants such as “communicatively coupled,” is generally used torefer to any engineered arrangement for transferring and/or exchanginginformation. Exemplary communicative pathways include, but are notlimited to, electrically conductive pathways (e.g., electricallyconductive wires, electrically conductive traces), magnetic pathways(e.g., magnetic media), and/or optical pathways (e.g., optical fiber),and exemplary communicative couplings include, but are not limited to,electrical couplings, magnetic couplings, and/or optical couplings.

Throughout this specification and the appended claims, infinitive verbforms are often used. Examples include, without limitation: “to detect,”“to provide,” “to transmit,” “to communicate,” “to process,” “to route,”and the like. Unless the specific context requires otherwise, suchinfinitive verb forms are used in an open, inclusive sense, that is as“to, at least, detect,” to, at least, provide,” “to, at least,transmit,” and so on.

The above description of illustrated embodiments, including what isdescribed in the Abstract, is not intended to be exhaustive or to limitthe embodiments to the precise forms disclosed. Although specificembodiments of and examples are described herein for illustrativepurposes, various equivalent modifications can be made without departingfrom the spirit and scope of the disclosure, as will be recognized bythose skilled in the relevant art. The teachings provided herein of thevarious embodiments can be applied to other portable and/or wearableelectronic devices, not necessarily the exemplary wearable electronicdevices generally described above.

For instance, the foregoing detailed description has set forth variousembodiments of the devices and/or processes via the use of blockdiagrams, schematics, and examples. Insofar as such block diagrams,schematics, and examples contain one or more functions and/oroperations, it will be understood by those skilled in the art that eachfunction and/or operation within such block diagrams, flowcharts, orexamples can be implemented, individually and/or collectively, by a widerange of hardware, software, firmware, or virtually any combinationthereof. In one embodiment, the present subject matter may beimplemented via Application Specific Integrated Circuits (ASICs).However, those skilled in the art will recognize that the embodimentsdisclosed herein, in whole or in part, can be equivalently implementedin standard integrated circuits, as one or more computer programsexecuted by one or more computers (e.g., as one or more programs runningon one or more computer systems), as one or more programs executed by onone or more controllers (e.g., microcontrollers) as one or more programsexecuted by one or more processors (e.g., microprocessors, centralprocessing units, graphical processing units), as firmware, or asvirtually any combination thereof, and that designing the circuitryand/or writing the code for the software and or firmware would be wellwithin the skill of one of ordinary skill in the art in light of theteachings of this disclosure.

When logic is implemented as software and stored in memory, logic orinformation can be stored on any processor-readable medium for use by orin connection with any processor-related system or method. In thecontext of this disclosure, a memory is a processor-readable medium thatis an electronic, magnetic, optical, or other physical device or meansthat contains or stores a computer and/or processor program. Logicand/or the information can be embodied in any processor-readable mediumfor use by or in connection with an instruction execution system,apparatus, or device, such as a computer-based system,processor-containing system, or other system that can fetch theinstructions from the instruction execution system, apparatus, or deviceand execute the instructions associated with logic and/or information.

In the context of this specification, a “non-transitoryprocessor-readable medium” can be any element that can store the programassociated with logic and/or information for use by or in connectionwith the instruction execution system, apparatus, and/or device. Theprocessor-readable medium can be, for example, but is not limited to, anelectronic, magnetic, optical, electromagnetic, infrared, orsemiconductor system, apparatus or device. More specific examples (anon-exhaustive list) of the computer readable medium would include thefollowing: a portable computer diskette (magnetic, compact flash card,secure digital, or the like), a random access memory (RAM), a read-onlymemory (ROM), an erasable programmable read-only memory (EPROM, EEPROM,or Flash memory), a portable compact disc read-only memory (CDROM),digital tape, and other non-transitory media.

The various embodiments described above can be combined to providefurther embodiments. To the extent that they are not inconsistent withthe specific teachings and definitions herein, all of the U.S. patents,U.S. patent application publications, U.S. patent applications, foreignpatents, foreign patent applications and non-patent publicationsreferred to in this specification and/or listed in the Application DataSheet which are owned by Thalmic Labs Inc., including but not limitedto: U.S. Non-Provisional patent application Ser. No. 15/167,458 (now USPatent Application Publication No. US 2016-0349514 A1), U.S.Non-Provisional patent application Ser. No. 15/167,472 (now US PatentApplication Publication No. US 2016-0349515 A1), U.S. Non-Provisionalpatent application Ser. No. 15/167,484 (now US Patent ApplicationPublication No. US 2016-0349516 A1), US Patent Application PublicationNo. US 2016-0377865 A1, US Patent Application Publication No. US2016-0377866 A1, US Patent Application Publication No. US 2016-0238845A1, US Patent Application Publication No. US 2017-0212290 A1, US PatentApplication Publication No. 2017-0068095, U.S. Provisional PatentApplication Ser. No. 62/534,099, U.S. Provisional Patent ApplicationSer. No. 62/565,677, U.S. Provisional Patent Application Ser. No.62/525,601, U.S. Provisional Patent Application Ser. No. 62/557,551,U.S. Provisional Patent Application Ser. No. 62/557,554, and U.S.Provisional Patent Application Ser. No. 62/573,978 are incorporatedherein by reference, in their entirety. Aspects of the embodiments canbe modified, if necessary, to employ systems, circuits and concepts ofthe various patents, applications and publications to provide yetfurther embodiments.

These and other changes can be made to the embodiments in light of theabove-detailed description. In general, in the following claims, theterms used should not be construed to limit the claims to the specificembodiments disclosed in the specification and the claims, but should beconstrued to include all possible embodiments along with the full scopeof equivalents to which such claims are entitled. Accordingly, theclaims are not limited by the disclosure.

1. A wearable heads-up display (WHUD) comprising: a support structure that in use is worn on a head of a user; a display light source to provide display light; and a transparent combiner carried by the support structure and positioned in a field of view of an eye of the user when the support structure is worn on the head of the user, the transparent combiner comprising: a curved waveguide; an in-coupler physically coupled to a first area of the curved waveguide, the in-coupler to receive display light from the display light source and in-couple display light into the curved waveguide; and an out-coupler physically coupled to a second area of the curved waveguide, the out-coupler to receive display light from the curved waveguide and out-couple display light into the field of view of the eye of the user.
 2. The WHUD of claim 1 wherein the in-coupler and the out-coupler are each selected from a group consisting of: a hologram, a holographic optical element, a volume diffraction grating, a surface relief diffraction grating, a transmission grating, and a reflection grating.
 3. The WHUD of claim 1 wherein the first area of the curved waveguide to which the in-coupler is physically coupled is an area on an outer surface of the curved waveguide.
 4. The WHUD of claim 1 wherein the second area of the curved waveguide to which the out-coupler is physically coupled is an area on an inner surface of the curved waveguide.
 5. The WHUD of claim 1 wherein the transparent combiner further comprises a curved eyeglass lens, and wherein the curved waveguide is at least partially embedded in an inner volume of the curved eyeglass lens.
 6. The WHUD of claim 5 wherein the curved waveguide is completely contained in the inner volume of the curved eyeglass lens.
 7. The WHUD of claim 5 wherein the curved eyeglass lens is a prescription eyeglass lens.
 8. The WHUD of claim 7 wherein the prescription eyeglass lens has a prescription curvature, and wherein a curvature of the curved waveguide matches the prescription curvature of the prescription eyeglass lens.
 9. The WHUD of claim 5 wherein the curved eyeglass lens includes a convex world-side surface and a concave eye-side surface.
 10. The WHUD of claim 9 wherein the out-coupler is positioned and oriented to apply a compensatory optical function to display light when the out-coupler out-couples display light from the curved waveguide, the compensatory optical function matched to an optical function of the convex world-side surface of the curved eyeglass lens.
 11. The WHUD of claim 5 wherein a length of the curved waveguide extends across a full width of the curved eyeglass lens.
 12. The WHUD of claim 11 wherein the second area of the curved waveguide to which the out-coupler is physically coupled is positioned at or proximate a center of the curved eyeglass lens.
 13. The WHUD of claim 1 wherein the first area of the curved waveguide is a first planar area of the curved waveguide and the second area of the curved waveguide is a second planar area of the curved waveguide, and wherein the in-coupler is a planar in-coupler physically coupled to the first planar area of the curved waveguide and the out-coupler is a planar out-coupler physically coupled to the second planar area of the curved waveguide.
 14. The WHUD of claim 1 wherein the first area of the curved waveguide is a first curved area of the curved waveguide and the second area of the curved waveguide is a second curved area of the curved waveguide, and wherein the in-coupler is a curved in-coupler physically coupled to the first curved area of the curved waveguide and the out-coupler is a curved out-coupler physically coupled to the second curved area of the curved waveguide.
 15. The WHUD of claim 1 wherein the display light source is selected from a group consisting of: a laser projector and a microdisplay.
 16. The WHUD of claim 1 wherein the support structure has a shape and geometry of a pair of eyeglasses. 